Im wondering if anyone has done any modifications to their Island tandem to make it better to withstand big waves and high winds.... Can rudder cables be replaced with beefier ones ? bracing of aka's and or ama's...etc...

Mine has not been modified and does not really seem to need it. I had it out yesterday in between the squall lines of TS Isaac. It was surprisingly calm for a tropical storm. Steady wind was only about 12-20, but some gusts up to 30. I used the full sail pretty much the whole time.

I have fitted spray skirts as per kayakingbob's design, and the side benefir is they also provide a secondary method of holding akas in their sockets. I am fitting tethers on the rear akas to do the same job.

Having had a rudder line break inside the hull during offshore wind conditions, I am fitting back-up external steering lines, one side with a bungee cord tensioner and the other with 2:1 tackle to increase precision while reducing the force needed to hold the steering line. Both sides will pass through small cam cleats for adjustability.

I have avoided tramps after reading of the potential for wind to get under the windward one in extreme conditions